Carrier for a windscreen wiper blade

ABSTRACT

A windscreen wiper blade carrier comprising a bowed stem with means for engaging a wiper arm, socket means at each tip and resilient snap-engaged support means comprising retainers for engagement with a blade. The carrier is adjustable at both ends so as to permit the attachment to the carrier of refill wiper blades of a plurality of different lengths. In one embodiment the tips of the carrier may be formed with longitudinally spaced socket means separated by lines of weakness to allow portions of the carrier to be broken off. It is preferred to form the end portions of the carrier as separate members which are telescopically received by the main carrier portions, there being cooperating means for locking the end portions in one of a plurality of predetermined positions to in one of a plurality of predetermined positions to adjust the effective length of the carrier.

The present invention relates to a carrier for a windscreen wiper. Thecarrier of a windscreen wiper for a motor vehicle is normally anelongate metal member which is detachably connectable to an arm which inturn is more permanently attached to a motor on the motor vehicle. Thecarrier has means for attachment to a wiper blade which in turn is anelongate piece of resiliently flexible material, normally rubber, whichis strengthened by a steel backing strip. The rubber blades get worn inthe course of service and need to be replaced. Replacement blades arenormally sold ready-attached to a carrier, mainly for the reason that itis a comparatively easy operation to change a complete windscreen wipercomprising carrier and blade, while it is rather more difficult to fit ablade to a carrier where it has to be supported at each end and atintermediate points. However the differences from one motor vehicle toanother mean that wiper replacements have to be stocked in a greatnumber of sizes which is a difficult retailing problem and adds to theexpense of the replacement unit.

The invention is aimed at reducing the number of carriers required tocover the full range of windscreen wipers.

In accordance with the invention there is provided a windscreen wiperblade carrier which is adjustable at both ends so as to permit theattachment to the carrier of refill wiper blades of a plurality ofdifferent lengths.

Preferably the carrier comprises socket means at each tip constructed soas to permit the attachment to the carrier refill wiper blades of aplurality of different lengths.

The main embodiment of the invention which is described hereafter isbased upon a carrier comprising a rigid bowed stem. However if desiredthe carrier may be formed in a plurality of flexibly linked sections.Carriers of this type are known in which the carrier is formed in twohinged sections with the blade conforming generally to the contour ofthe carrier, the hinge sections being resiliently stressed in thedirection of the chord so that the wiper blade conforms to the contourof the windscreen. In the description which follows it will becomeapparent that the construction of the end portions of the rigid carriermay be readily adapted to a flexible carrier.

In accordance with a preferred form of the invention there is provide acarrier for a windscreen wiper comprising a rigid bowed stem with meansfor engaging a wiper arm and having a chord length correspondinggenerally with the length of a wiper blade, socket means at each tip forreceiving a respective end of a wiper blade, support means extendingfrom the stem towards the chord for engaging a wiper blade at at leasttwo points intermediate of the tips, the support means comprisingrespective retainers for engaging with a blade at the said points toresist lateral bowing of a fitted blade and to provide resilient forceto press such blade against a windscreen, wherein the socket means areconstructed to allow the fitting of blades of a plurality of differentlengths.

Preferably the support means comprise resilient arms. However they couldbe provided e.g. by rigid arms with a spring connection to the stem. Thestem may be of channel shape, open to the chord. It may have a centralaperture fitted with a pin for receiving a wiper arm tip in the normalway and the support means may comprise a member having a pair of springarms joined by generally parallel webs formed to seat within theaperture. The webs may each have a recess formed to snap-engage with thepin to hold the support member in position.

In the preferred case, the end portions of the stem are separate from amain stem portion and are telescopically received by the main stemportion, each end of the main stem portion and its corresponding endportion comprising cooperating means for locking the end portion in oneof a plurality of predetermined positions to adjust the effective lengthof the stem. Each stem end portion may be of channel shape and receivedwithin the channel of the main stem portion, the latter comprising atleast one flange at each end to partly enclose the corresponding endportion.

In the preferred embodiment the locking means comprises a row of equallylongitudinally spaced cooperating projections and recesses by which eachend portion can snap-engage with the main stem portion in differentportions. Preferably the projections project inwards from both channelside walls of the main stem portion to engage with recesses on the sidewalls of the end portion. Preferably the sockets are formed as dimples.

In an alternative arrangement, the locking means may comprise a movablepin connected to each end of the main portion and receivable in one of arow of holes in each stem end portion.

In another embodiment each tip of the stem may be formed with aplurality of longitudinally spaced socket means separated by lines ofweakness to allow unwanted end portions of the stem to be broken off.

Embodiments of the invention are hereafter described with reference tothe accompanying drawings, in which:

FIG. 1 is a side elevational view of a carrier in accordance with theinvention;

FIG. 2 is a plan view, viewed from the chord, of the carrier of FIG. 1;

FIG. 3 is a section along the line III--III of FIG. 1;

FIG. 4 is a side elevational view corresponding to FIG. 1 of the supportmember;

FIG. 5 is an end view of one of the support blades;

FIG. 6 is a perspective view of an end portion of the carrierillustrating the means for adjusting and locking the tip portions;

FIG. 7 is a side elevational view of part of a second embodiment ofcarrier; and

FIG. 8 is a view corresponding to FIG. 7 of a third embodiment.

In FIGS. 1 to 6 the carrier shown generally in FIG. 1 comprises a rigidbowed stem 10 of channel shape having a back portion 11 and side walls12, the channel being open to the chord C. Although the stem may have acurved bow, in this embodiment the bow is formed by rectilinear arms10a, 10b arranged to extend at a dihedral angle of about 10° from acentral connection portion 10c which is formed with an aperture 13between the side walls 12. A pin 14 extends across the aperture in aconventional manner for receiving a wiper arm tip and may be e.g.riveted in place between the side walls 12 which are formed withsuitable bores. The main stem member constituted by portions 10a, 10band 10c, may be formed of pressed steel.

Mounted within the recess 14 is a support member 15 shown in more detailin FIG. 4. This member may also be formed of pressed steel and comprisesa pair of spring arms 16,17 joined by generally parallel webs, one ofwhich is shown at 18. The webs have recesses 19 which are generallykeyhole-shaped to enable the member 15 to be snap-engaged in theaperture 13 around the pin 14. At the end of each arm 16,17 is afastening means 20, shown in more detail in FIG. 5, which is generallyof channel shape with claws 21 at the ends of the side walls to engageand hold the steel backing strip of a rubber wiper blade.

The purpose of the support means is to engage the wiper blade at twopoints intermediate of the tips of the carrier to resist lateral bowingof the fitted blade and to provide the necessary resilient force topress the blade against a curved windscreen over its full length.

End portions of the stem 10 are formed as separate members 21,22, one ofwhich 22 is shown in more detail in FIG. 6 and will be described. Themembers 21 and 22 are mirror images one of the other as will beapparent. The member 22 is also preferably of pressed steel and is ofchannel section corresponding to that of stem portion 10b. It istelescopically received into the end of the portion 10b and partiallyenclosed by flanges 23 in spaced positions at the ends of the portions10a and 10b as shown more clearly in FIG. 2. At the end of theextendable portion 22 is a claw 24 formed by flanges in side walls 25 ofthe portion 22. The side walls 25 are connected by a web 26.

The portions 22 may be telescopically withdrawn from the main stemportion by equal increments so that the effective length of the carriercan be adjusted to suit different blade sizes required for differentmotor vehicles. Means are provided for locking the extendable portions22 at different predetermined positions and in this embodiment this isprovided by rows of inter-engaging dimples on the main stem portion andthe extendable portions. Thus a row of dimples formed to constituteprojections 27 is formed in each side wall 12 so that pairs ofprojections face each other across the channel. These projections 27engage within complementary recesses 28 formed by inwardly projectingdimples in the side walls 25 of the extendable stem portions 21,22 asshown particularly in FIG. 6. The dimples on both portions may be spacede.g. 10 mm apart so that by extending each extendable portion 21,22 byone increment, the effective length of the carrier may be extended by 20mm to the next size of blade. Naturally, however, the spacing andpositioning of the dimples will be suited to the prevailing range ofblade sizes. The inner end of the extendable portion 22 may be taperedas shown to provide a convenient lead-in and the outward or tip end mayhave chamfered side walls leading to the claw 24 which should ofappropriate height from the web 26 to grip the end of a blade.

The inter-engaging projections 27 and recesses 28 engage along the rowby snap fitting, making use of the resilient qualities of the channelsections involved. The inter-engagement may be sufficiently firm torequire the use of tools if desired since, normally, the correctadjustment of length will be performed as part of the manufacturing orpackaging operation prior to retailing and not by the eventual customer.However as practices change, the tolerances may be such as to providethe facility of adjustment by hand by the eventual customer.

Turning to FIG. 7 there is shown an embodiment in which theinter-locking dimples of the previous embodiment are replced by a seriesof holes 30 in the web of the extendable portion which is marked 22' andwhich can be engaged by a pin 31 formed on an arm 32 which is connectedto the end of the main stem portion 10' e.g. by a riveted connectionwhich allows the arm to swivel. By lifting the end of the arm and pinthe portion 22 can be withdrawn or replaced by a desired number ofincrements and the pin allowed to engage in a new hole.

Turning to FIG. 8 there is shown an alternative embodiment in which thestem is formed with a plurality of longitudinally spaced socket means inthe form of claws 24' separated by lines of weakness 40 which allowunwanted end portions of the stem to be broken off. Thus in theembodiment illustrated, the end portion 41 may be broken off at thefirst line of weakness 40 to shorten the effective length of the carrierby one increment.

We claim:
 1. A windscreen wiper blade carrier comprising a bowed mainstem including a central portion for engaging a wiper arm and first andsecond end portions, a first extension arm telescopicly received by saidfirst end portion and a second extension arm telescopicly received bysaid second end portion, said first and second extension arms beingindependent of each other and including first and second socket means,respectively, for attachment to a wiper blade, whereby said wiper blademay be engaged only at selected locations between its ends and remainsubstantially free of contact therebetween, and wherein the distancebetween said first and second socket means comprises a chord lengthwhich can be adjusted by telescopicly adjusting said first and secondextension arms with respect to said first and second end portions ofsaid bowed main stem and said wiper blade carrier can thereby acceptwiper blades having a plurality of different lengths.
 2. The windscreenwiper blade carrier of claim 1, including engaging means for engagingsaid wiper blade at additional selected locations between said points ofattachment of said first and second socket means.
 3. The windscreenwiper blade carrier of claim 2, wherein said engaging means comprisessupport means affixed to said central portion of said bowed main stem,said support means including a central portion, a first end and a secondend, and third and fourth socket means located at said first and secondends of said support means for attachment to said wiper blade at saidadditional selected locations intermediate of said points of attachmentof said first and second socket means.
 4. The windscreen wiper bladecarrier of claim 3, wherein said support means comprises first andsecond resilient arms whereby lateral bowing of said wiper blade isresisted and a resilient force is provided so as to press said wiperblade against a windscreen between the ends thereof.
 5. The windscreenwiper blade carrier of claim 1, wherein said first and second extensionarms have generally U-shaped cross-sections comprising a base portionand a pair of side wall portions defining a channel portiontherebetween.
 6. The windscreen wiper blade carrier of claim 3, whereinsaid side walls of said first and second extension arms include taperedend portions.
 7. The windscreen wiper blade carrier of claim 1, whereinsaid bowed main stem has a generally U-shaped cross-section comprising abase portion and a pair of side wall portions defining a channel portiontherebetween, with said channel portion being open to said chord.
 8. Thewindscreen wiper blade carrier of claim 7, wherein said central portionof said bowed main stem includes a central apperture for receiving a pinmember for attachment to a wiper arm.
 9. The windscreen wiper bladecarrier of claim 8, including support means affixed to said centralportion of said bowed main stem, said support means including a centralportion, a first end and a second end, and third and fourth socket meanslocated at said first and second ends of said support means forattachment to said wiper blade at additional selected locationsintermediate of said points of attachment of said first and secondsocket means, said support means further comprising a pair of parallelweb members at said central portion formed to seat within said centralportion of said bowed main stem including said central apperture, afirst spring arm associated with said first end of said support meansand a second spring arm associated with said second end of said supportmeans.
 10. The windscreen wiper blade carrier of claim 9, wherein eachof said pair of parallel web members includes a recessed portion formedfor snap engagement with said pin member so as to retain said supportmember within said central portion of said bowed main stem.
 11. Thewindscreen wiper blade carrier of claim 1, including locking means forlocking said first and second extension arms in a plurality ofpredetermined positions with respect to said bowed main stem.
 12. Thewindscreen wiper blade carrier of claim 11, wherein said locking meanscomprises corresponding rows of equally spaced projections and recesses,whereby each of said plurality of predetermined positions of said firstand second extension arms with respect to said bowed main stem aredetermined by a pair of said corresponding projections and recesses. 13.The windscreen wiper blade carrier of claim 12, wherein said pluralityof projections are associated with said first and second ends of saidbowed main stem and said plurality of corresponding recesses areassociated with said first and second extension arms.
 14. The windscreenwiper blade carrier of claim 11, wherein said locking means comprises apair of movable pin members projecting from the first and second endportions of said bowed main stem and a corresponding plurality ofapertures located on said first and second extension arms, whereby saidplurality of predetermined position of said first and second extensionarms with respect to said bowed main stem are determined by one of saidplurality of apertures into which said pin members are inserted.